Abiotic aquatic terrestrial
Hubewan 10:20, May 3, 2010 (UTC) Viscosity Viscosity is a measure of how difficult it is to move through a substance. In other words, it is the measure of flow rates. It is an important feature of aquatic environments.' '''Viscosity is an issue that affects aquatic environments. Viscosity does not affect terrestrial environments as air is not viscous as all. In an aquatic environment, however, viscosity is an important factor as an animal that lives in water requires a streamlined shape. Buoyancy '''Buoyancy' is a measure of a substance’s ability to support or hold up an object. Buoyancy is not an issue on land and does not affect what kinds of organisms live on land. However, buoyancy affects what organisms live in sea. They cannot be too heavy. If, however, they were heavy, they would need to be so massive so that the buoyancy of water can support them. Temperature Variation Temperature variation is the change of temperature. It is larger on land than it is at sea, with fluctuations of usually 15-20 degrees. At sea, however, temperature variation is low as the specific heat of water is very high while the specific heat of rock and air is low. This affects the type of animals that live on land but not at sea. The specific heat of water is four times higher than the specific heat of rock. Conduction of heat Conduction of heat refers to how well temperature diffuses between substances. Water can conduct heat really well. This is what causes unprotected land mammals to die in water – because of hypothermia where the water has absorbed all the heat. Availability of gases Availability of gases describes which of the key gases are available. This includes oxygen and carbon dioxide for respiration and photosynthesis respectively. The availability of gases is not an issue on the ground. However, it is an issue at sea. On the surface of the sea, there is plenty of oxygen and carbon dioxide to diffuse into the water. However, as one goes deeper, there is less and less oxygen. It is also colder in the sea as it is deeper. Diffusion of gases Diffusion of gases is the movement of gases through water and air. It shows the movement of gases from a higher concentration area to a lower concentration area. Availability of water Availability of water is an issue on land. Water on land is not spread evenly and is not a common resource. It is used by organisms and is lost through evaporation, whether it is consumed or not. The availability of water on land depends on precipitation. In a freshwater environment, which includes rivers, streams and lakes, it also relies on precipitation. In the sea, availability of water is not an issue. Some terrestrial lifeforms have developed ways to conserve and store water. Examples of these include cacti and desert animals. Ions are available in soil water. In a terrestrial environment, the amount of ions or nutrients that are available depends on the amount of soil water that is available. If there is a lot of soil water, there are generally more ions available. If there is not a lot of soil water, there are generally less ions available. However, too many ions would prevent plant growth. The need for ions only affects terrestrial environments. Light Light is available in abundance in terrestrial environments, the only exceptions being enclosed areas such as caves and caverns. In an aquatic environment, light is not an issue. However, when one goes deeper, they reach the so called “twilight zone” and eventually a dark zone. Pressure changes On the surface, there are frequent '''pressure changes. '''It is these pressure changes that affect temperature and rainfall changes. These variations on land are small and do not directly affect the survival of an animal. However, in an aquatic environment, there are vast differences between the pressure at the bottom of the ocean and the top of the ocean. An animal that lives near the top of the ocean and is not designed to survive the pressures experience near the bottom is likely to be crushed by the pressure. To tabulate this Category:Notes Category:Preliminary Category:A Local Ecosystem